Fluid pressure motor for an automatic mooring winch



March 15, 1956 SEKKELSTEN 3,240,126

FLUID PRESSURE MOTOR FOR AN AUTOMATIC MOORING WINCH Filed June 27, 1965 lnvenfor Arne Sekke/sfen By his Arforneys United States Patent 3,240,126 FLUID PRESSURE MOTOR FOR AN AUTOMATIC MOGRING WINCH Arne Sekkelsten, Moss, Norway, assignor to Pusner Mek. Verksted A/ S, Arendal, Norway Filed June 27, 1963, Ser. No. 291,179 2 Claims. (Cl. 91420) The invention relates to a fluid pressure motor, preferably of the reciprocating piston type, for a steam driven, automatic mooring winch of the type where a mooring wire is fastened to the drum of the winch, on which drum the wire is automatically wound up or unwound so that the mooring wire is automatically held in the desired tight condition.

Several types of such automatic mooring winches have been previously known. Especially where these are driven by steam, there is, however, the disadvantage that when the stretch in the wire is greater than normal, so that the winch gives out wire, the inertness of the mechanical transmission parts of the winch will be added to the resistance set up by the steam engine or motor which drives the winch when it is forced to move against the direction in which it is set to revolve.

The total stress which is then effected has in many cases resulted in a broken wire or has caused the winch to be torn away from its base.

The object of the invention is to eliminate this disadvantage, and this is done by providing a fluid pressure actuated motor of the reciprocating piston type having in the exhaust pipe thereof a pressure relief or throttle valve, which valve is automatically controlled by the pressure of the steam from the supply pipe. By this arrangement of control mechanism, the difference in pressure be tween the two sides of a working plunger subject on its top side to the pressure existing in the fluid pressure supply pipe leading to the cylinder of the fluid pressure actuated motor, which plunger is operatively connected to the pressure relief or throttle valve, will be reduced to a predetermined extent, whereby one does not get such great resistance from the fluid pressure actuated motor when the wire is pulled off the drum of the automatic mooring winch.

For a better understanding of the invention, reference is had to the schematic embodiment shown in the accompanying drawing, wherein:

1 represents the supply pipe for supplying fluid pressure such as fresh steam to the working cylinder C of a fluid pressure actuated motor of the reciprocating piston type, such as a steam engine, in which cylinder the piston 3 reciprocates. 2 is the intake and exhaust valve for directing of the steam supply to the cylinder C or to the exhaust outlet. 4 is the exhaust pipe for exhaust steam from working cylinder C. The valve 2 is of the conventional four-way type usually employed to control the admission of steam or other fluid pressure to the working cylinder of a reciprocating piston type motor or engine and to control the exhaust of steam or other fluid pressure therefrom.

In the example shown, a valve arrangement V is inerted in the exhaust pipe 4. This valve arrangement consists of a pressure reducing valve 5 which functions as a throttle valve and controls the flow of exhaust steam or other fluid pressure from the working cylinder to a discharge pipe 9. The pressure reducing or throttle valve 5 is rigidly connected by a stem or spindle to a plunger 6, which on the top thereof is exposed to the pressure of fresh steam or other fluid pressure existing in supply pipe 1, the valve housing V here being connected by a branch pipe 7 to supply pipe 1, said branch pipe 7 serving to supply steam or other fluid pressure from supply ice pipe 6. A by-pass pipe 8 connects the branch pipe 7 to the exhaust pipe 4 and extends from a point in branch pipe 7 above plunger 6 to a point in exhaust pipe 4 in advance of or upstream of valve housing V as shown, for the establishment of the desired pressure differential.

The overall area of the valve 5 subject to pressure existing in the exhaust pipe 4 is considerably greater than the overall area of the plunger 6 subject to the pressure existing in the supply pipe 1 and its connected branch pipe 7. The pressure relief or throttle valve 5 is thus loaded against the pressure of the exhaust steam or other fluid pressure existing in pipe 4 by the pressure of the fresh steam or other fluid pressure existing in supply pipe 1 and its connected branch pipe 7 and which is effective on the top of the plunger 6. Because of said difference in area, the pressure relief or throttle valve 5 will open for discharge of the exhaust steam or other pressure fluid from exhaust pipe 4 to discharge pipe 9.

Variations in the pressure P in the fresh steam or other fluid pressure supply pipe 1 and its connected branch pipe 7 will, by this arrangement of mechanism, automatically affect the pressure effective on the top of plunger 6, and will also regulate the counter pressure for the opening of the valve 5 for exhaust steam or other fluid pressure from exhaust pipe 4 and through discharge pipe 9.

By increasing the pressure P in the exhaust pipe 4 by means of by-pass line 8, because of the loaded valve 5, the pressure differences P P in the cylinder C are reduced, which reduction results in less engine resistance when the wire is unwound from the drum of the mooring winch.

When the automatic winch is used for mooring, i.e. for manual operation, the valve V can be put out of automatic action by suitable means. In the schematic example shown in the drawing, this is effected by connecting valve 5 with a rod or spindle 10, which extends downwardly from valve 5 and is pivotally connected at its lower end to a lever 11, which lever 11 rests upon a fulcrum positioned intermediate its ends, and which lever 11 is provided at the other end with a pedal 12. This pedal 12 is pressed down when the winch is to be manually operated, and is released when it is desired that the winch again shall work automatically. Suitable springs (not shown) may be part of this arrangement, to secure the desired functioning of valve 5 upon release of the pedal 12, to return the mechanism to automatic operation.

I claim:

1. In a fluid pressure actuated motor of the reciprocating piston type including a cylinder; a piston therein; a four-way valve connected to and communicating with said cylinder to control, alternatively, the inlet and exhaust of fluid pressure to said cylinder to cause reciprocation of said piston within said cylinder; a fluid pressure supply pipe and an exhaust pipe connected to said valve; a throttle valve in said exhaust pipe to regulate the flow of exhaust fluid therethrough from said cylinder, said throttle valve having a surface exposed to the pressure existing in said exhaust pipe; a housing enclosing said throttle valve and provided with an extension above said throttle valve; a plunger in said extension above and connected to said throttle valve; a branch pipe connecting said supply pipe to said extension of said housing at a point above said plunger so that fluid pressure in said sup- .ply pipe is effective on the upper surface of said plunger, said upper surface of said plunger having an overall area less than the overall area of the surface of said throttle valve exposed to the pressure in said exhaust pipe; and by a by-pass pipe connecting said branch pipe at a point above said plunger with said exhaust pipe at a point upstream of said throttle valve.

2. A fluid pressure motor as defined in claim 1, includ- References Cited by the Examiner UNITED STATES PATENTS Rowntree 91-165 Bath 91-335 Rowntree 91420 Monroe 91420 4 FOREIGN PATENTS 535,931 10/1931 Germany.

OTHER REFERENCES German printed application No. 1,036,598, August 14, 1958.

SAMUEL LEVINE, Primary Examiner. 

1. IN A FLUID PRESSURE ACTUATED MOTOR OF THE RECIPROCATING PISTON TYPE INCLUDING A CYLINDER; A PISTON THEREIN; A FOUR-WAY VALVE CONNECTED TO AND COMMUNICATING WITH SAID CYLINDER TO CONTROL, ALTERNATIVELY, THE INLET AND EXHAUST OF FLUID PRESSURE TO SAID CYLINDER TO CAUSE RECIPROCATION OF SAID PISTON WITHIN SAID CYLINDER; A FLUID PRESSURE SUPPLY PIPE AND AN EXHAUST PIPE CONNECTED TO SAID VALVE; A THROTTLE VALVE IN SAID EXHAUST PIPE TO REGULATE THE FLOW OF EXHAUST FLUID THERETHROUGH FROM SAID CYLINDER, SAID THROTTLE VALVE HAVING A SURFACE EXPOSED TO THE PRESSURE EXISTING IN SAID EXHAUST PIPE; A HOUSING ENCLOSING SAID THROTTLE VALVE; A PLUNGER IN SAID EXTENSION ABOVE SAID THROTTLE VALVE; A PLUNGER IN SAID EXTENSION ABOVE AND CONNECTED TO SAID THROTTLE VALVE; A BRANCH PIPE CONNECTING SAID SUPPLY PIPE TO SAID EXTENSION OF SAID HOUSING AT A POINT ABOVE SAID PLUNGER SO THAT FLUID PRESSURE IN SAID SUPPLY PIPE IS EFFECTIVE ON THE UPPER SURFACE OF SAID PLUNGER, SAID UPPER SURFACE OF SAID PLUNGER HAVING AN OVERALL AREA LESS THAN THE OVERALL AREA OF THE SURFACE OF SAID THROTTLE VALVE EXPOSED TO THE PRESSURE IN SAID EXHAUST PIPE; AND BY A BY-PASS PIPE CONNECTING SAID BRANCH PIPE AT A POINT ABOVE SAID PLUNGER WITH SAID EXHAUST PIPE AT A POINT UPSTREAM OF SAID THROTTLE VALVE. 